Conventionally, power transmission devices are known to change an input-to-output rotational (the number of revolutions) ratio, that is, a transmission ratio. Among the power transmission devices is a continuously variable transmission for continuously variably changing a transmission ratio, such as one composed of a so-called traction planetary gear mechanism that includes a plurality of rotating elements. An example of a traction planetary gear mechanism includes: first to fourth rotating elements which can rotate relative to one another with a common rotation center axis; and rolling members, as a fifth rotating element, which have rotation center axes different from the common rotation center axis. The first rotating element is obtained by molding in a columnar or cylindrical form, and functions as a sun roller. A plurality of rolling members (planetary balls) are radially arranged on the periphery of the first rotating element. The second rotating element functions as a carrier and rotates (revolves) together the rolling members supported by the carrier around its rotation center axis. The third and fourth rotating elements are obtained by molding in an annular or disk-like form and function as ring gears in a planetary gear mechanism, and sandwich the rolling members. The rolling members rotate around their rotation center axes, in addition to their individual revolving. In a traction planetary gear mechanism of this type, torque is transmitted among the first, second, third, and fourth rotating elements via each rolling member. For example, Patent Literature 1 described below discloses a continuously variable transmission of this type. In the continuously variable transmission described in the Patent Literature 1, respective portions of planetary balls are surrounded by the annular portions of pivotal support objects, and these are integrated by extending a support shaft through them. The support shaft passes through the center of each planetary ball. Each pivotal support object is supported by the carrier by fitting a notch thereof on a pin extending from the carrier. Thus, each planetary ball revolves integrally with the carrier. In the continuously variable transmission described in the Patent Literature 1, adjacent planetary balls are connected by a thin rod-like member both ends of which are fitted into the annular portions of the pivotal support objects.